hardware: Microarchitectural Data Sampling Uncacheable Memory (MDSUM)

Microarchitectural Data Sampling Uncacheable Memory (MDSUM): Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. A list of impacted products can be found here: https://www.intel.com/content/dam/www/public/us/en/documents/corporate-information/SA00233-microcode-update-guidance_05132019.pdf